The present invention pertains to a process and a folding device for folding or folding over the edges of the pocket cuts with round edge sections during the preparation of pockets sewn on pieces of garments using a folding device arranged on a sewing unit with a pocket support plate, which folding device can be moved up and down as well as forward and backward in relation to a fabric support plate, with a pressing plate, which can be moved up and down, as well as with a plurality of the folding slides, which can be moved up and down together with the pressing plate and can be moved forward and backward individually or together, of which the round folding slides used to form the round edge sections have a concave folding edge
A folding device for folding over the edges of pockets of various shapes has been known from DE-PS 1 660 924. In DE-PS 1 660 924 a folding device is disclosed in FIG. 10 for folding over pockets with a round edge section, which has folding slides with a folding edge extending in a straight line for folding over the straight edge sections and round folding slides with a concave folding edge for folding over the round edge sections. The radius of this folding edge corresponds to the radius of the round edge section of the pocket to be formed. It was found that an unsatisfactory result is obtained with folding device of such a design insofar as deviations from the desired arc shape will occur during folding, especially at the transitions between the straight and arc-shaped edge sections in the area of round edge sections because of the material gatherings occurring there, besides nonuniformly formed creases, due to the fact that bulges of the folded edge, which bulges are folded in incompletely, are left, which lead to nonuniform seams in this area and consequently to an unattractive appearance of the pocket sewn on. The smaller the radius of the round edge section, the more marked will be such irregularities and disturbances.
A folding device for folding or folding over pockets, which has a pocket support plate that can be moved forward and backward, a pressing plate that can be moved up and down, and a plurality of folding slides, which can be moved forward and backward and are arranged on a frame that can be moved up and down, has been known from DE 40 08 148 C2 (corresponding to U.S. Pat. No. 5,058,517). L-Shaped elastic clamping pieces are fastened to the folding slides, and these clamping pieces generate an increased clamping force acting on the pocket support plate located between them, the pocket cut and the pressing plate together with the folding slides when they are moving forward together into the folding position. A clean folding result is thus obtained even when the difference in the levels of the folding slides and the pocket support plate is not exactly adjustable. Moreover, pocket cuts with round edge sections can also be folded accurately. Folding slides arranged at an angle of 45xc2x0 with a concave folding edge and with a clamping piece each are associated with the round corner areas of the pocket cut for this purpose. However, no reference can be found on how the material gatherings occurring there are uniformly distributed; at any rate, an increased clamping force is not a remedy.
Pocket shapes with round edge sections can be found, e.g., in the prospectus Adler-Automation 802-20/ZE 2-2 (1973). However, there is no reference to any measure for solving the problem of material gatherings occurring in the case of round edge section and the corresponding sewing unit does not have such an embodied measure, either.
The basic object of the present invention is to provide a process and a folding device by which the material gatherings occurring in the area of the round edge sections are uniformly distributed.
According to the invention, a process is provided for folding or folding over the edges of the pocket cuts with round edge sections during the preparation of pockets sewn on pieces of garments using a folding device arranged on a sewing unit. The sewing unit has a pocket support plate, which can be moved up and down as well as forward and backward in relation to a fabric support plate. A pressing plate is provided which can be moved up and down. A plurality of folding slides can be moved up and down together with the pressing plate and can be moved forward and backward individually or together. Round folding slides used to form the round edge sections have a concave folding edge. During the forward movement into the folding position, the round folding slides lead with at least one of the two ends of their concave folding edges in relation to the middle area of the folding edges.
According to a further aspect of the invention, a folding device is provided for carrying out the process. During the folding operation, at least one end of the concave folding edges of the round folding slides has a shorter distance from the respective associated convex folding edge of the said pocket support plate than the rest of the area of the concave folding edges.
Due to the measure taken in the process according to the invention and with the features of the device according to the invention, a more intense folding effect is exerted on the transition areas of the round edge sections to the straight edge sections than on the other areas of the round edge sections. It is thus achieved that these edge areas of pockets with round edge sections, which were problematic before, will also be folded over correctly, as a result of which a uniform seam will now be obtained over the entire course of the seam of the pocket sewn on.
In a variant of the process, the round folding slides are moved forward into the folding position one after another in different angular positions. Since one of the ends of the concave folding edges of the round folding slides thus has a shorter distance from the associated folding edge of the pocket support plate, the corresponding transition area of the round edge sections to the straight edge sections is folded over first during the feed motion of the round folding slides until the rest of the area of the round edge sections including the other transition area is finally folded over as well. After all folding slides are in their folding position and lie on the piece of clothing due to being lowered together with the pressing plate, only the round folding slides are retracted from the folding position, pivoted into the other angular position and are then again moved forward into their folding position. Since the other ends of the concave folding edge now have a shorter distance from the convex folding edge of the pocket plate, the other transition areas are now also folded over more intensely during the second folding operation, so that all transition areas are folded in to an increased extent to conclude the entire folding operation.
The folding effect of the ends of the concave folding edges, which ends are pivoted forward, is also supported by the possibility that the movement of the round folding slides may take place at a steeper angle in relation to the straight edge section joining the corresponding transition area than in the case of the usual round folding slides moved at an angle of 45xc2x0.
A comparatively simple device embodiment of the process may be formed by a corresponding shape of the folding edge of the round folding slides.
The possible further measures of the invention provide additional contributions to the optimal solution to the problem, namely, that the material gatherings occurring in the area of the round edge sections be distributed uniformly.
The number and the position of the creases formed during the folding over are determined by the notches on the folding edge, as a result of which uniform appearance of the two round edge sections of the same pocket but also of all other pockets is achieved.
It may be achieved that the areas of the pocket cuts adjoining the pocket cut edges to be folded over will be held absolutely securely during folding over, so that satisfactory clean folded edges, which also have a correct course corresponding to the pattern in the case of patterned fabrics, are obtained without the risk of a unilateral stretching of the pocket.
The use of a heating device within the pressing plate can provide an ironing effect, which stabilizes the shape and the position of the folded edges of the pocket cut, is exerted on the folded edges, so that the result of the folding is improved, especially also in the area of the round edge sections.
A measure may be provided to additionally improve the result of the folding in the case of differences in the thickness of the piece of clothing and/or of the pocket cut, which are caused by the number of fabric layers being different.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated.